1. Field of the Invention
The invention relates to an image forming apparatus and an image forming system that performs an image formation on the basis of image data outputted from an image processing apparatus and ejects record medium finished with image formation, in particular, relates to an image forming apparatus and an image forming system that not only can improve secrecy performance of image data, but also can prevent the record medium finished with image formation from being taken by other people.
2. Related Background Art
As a printing system (i.e. image forming system), a system comprising at least one user terminal (i.e. image processing apparatus) and a printing apparatus (i.e. image forming apparatus) connecting with the at least one user terminal via communication line is used.
In the printing system, after print data (i.e. image data) to be printed is transmitted to the printing apparatus from the user terminal, the print data is printed (i.e. is performed an image formation) onto print paper by the printing apparatus, then, the print paper on which the print data has been printed is ejected from the printing apparatus as record medium finished with image formation.
Beforetime, in order to prevent the record medium finished with image formation from being taken by other people, for example, as stated in a patent document 1 mentioned below, a non-contact type IC card carried by user is designed, after the user is identified by the printing apparatus through using the non-contact type IC card, whereafter, in the case that the user is in the place, a print of corresponding print data is performed as an identification print.
Whereas, in such printing system, because that the print data is transmitted from the user terminal to the printing apparatus via the communication line, there is a possibility that the print data is purloined by a purloining action of communication interception through using computer connected with the communication line. In order to inhibit such purloining action, a method is adopted to transmit the print data to the printing apparatus after encrypted the print data in the user terminal.
Patent document 1: Japan patent publication 2005-335282.
However, in such encrypting method, because a settled and identical encrypting key is always set in each user terminal, the respective print data all are encrypted by the identical encrypting key. Thereby, the purloining people can easily decipher the encrypting method from respective purloined data and obtain the print data. Therefore, in the case that the print data is data with high secrecy performance, the user (i.e. client) will sustain great damage.